Thin LED collimator with free-form lens array for illumination applications

2012 ◽  
Vol 51 (30) ◽  
pp. 7200 ◽  
Author(s):  
Emil Aslanov ◽  
Leonid L. Doskolovich ◽  
Mikhail A. Moiseev
Keyword(s):  
2013 ◽  
Vol 552 ◽  
pp. 131-136
Author(s):  
Yan Jun Sun ◽  
Yan Bing Leng ◽  
Zhe Chen ◽  
Lian He Dong

Free-form lens is a special element with non-rotating body and aspheric structure. The surface can’t be expressed by stationary analytic formula, and generally it expressed by discrete list point. Free-form lens can distribute light intensity freely,and control light angle、optical path difference etc. Specific light spot is formed in illumination surface, meanwhile the light energy utilization ratio is improved greatly. There are two kinds of methods about Free-form fabrication, and the first kind of method is that free-form is grinded by a small grinding head ,which is controlled by computer; its disadvantage is low precision、high waster rate,especially for optical material; The second kind fabricating method is that multi-degree-of-freedom single-point diamond turning equipment; its disadvantage is that plenty of sub-micron crack formed when brittle material fabricated. In addition, micro-lens array element can’t be fabricated by the two kinds of methods. In allusion to the feature of free-form without stationary analytic formula ,which varying dose exposure lithography method for free-form micro-optical element is presented for free-form micro-lens and array. The method is from the theory that the relation between different exposure energy and different developing depth, adopting laser direct writing equipment free-form photoresist structure is formed in material surface, then the free-form photoresist structure is transfered on the substrate by ion etching method. Any surface figure can be fabricated by controlling every point laser energy for this method, and surface roughness can’t be effected because ion etching belongs to nanofabrication. In this paper, that low Distribution of light amplitude and relation of between exposure energy and exposure time was analysised on base of optical propagation theory and mathematical model of light distribution law was built and simulated by computer program.The results indicate that light energy distributes in accordance with specific law; the exposure depth increases with exposure time. The experiment of exposure and developing finished, used the BOL-500 laser direct writing system in Changchun University of Science and technology,american Futurrex62A photoresist, 412nn He-Ne laser device, 5‰NaOH developing solution. The experimental data coincide with simulation result via comparative analysis. Meanwhile,a set of free-form micro-lens array testing system was established and focal spot shape,energy distribution,focal distance,F parameter were tested about the micro-lens array.


2020 ◽  
pp. 147715352095845
Author(s):  
Zhenmin Zhu ◽  
Zhiyu Wang ◽  
Fumin Zhang

Lighting-emitting diodes are widely applied in lighting systems, and diffusers are commonly used in systems for indirect illumination. In this paper, a design method of diffuse transmission free-form surface combined with collimation lens array is proposed. Based on the Lambertian characteristics of lighting-emitting diodes and the principle of collimation lenses, a mathematical model of diffuser with ideal diffuse transmission free-form surface is established. We propose a method of the preset collimation surface to connect the free-form surface and the collimation lens array, and derive the nonlinear algebraic equation of the diffuse transmission free-form surface according to the connection effect of the preset collimation surface. Then, solving the equation numerically by MATLAB, the profile of the diffuse transmission free-form surface is obtained. Finally, the non-sequential ray tracing software TracePro is used to simulate the irradiance distribution of the target plane. The results show better uniformity and higher efficiency comparing with the lighting system using diffuse transmission free-form surface alone and the traditional diffuse transmission lighting system.


2013 ◽  
Author(s):  
Zhao Wu ◽  
Hongda Sun ◽  
Shusen Jiang ◽  
Miao Lu

2002 ◽  
Vol 41 (03) ◽  
pp. 129-134 ◽  
Author(s):  
A. Wolski ◽  
E. Palombo-Kinne ◽  
F. Wolf ◽  
F. Emmrich ◽  
W. Becker ◽  
...  

Summary Aim: The cellular joint infiltrate in rheumatoid arthritis patients is rich in CD4-positive T-helper lymphocytes and macrophages, rendering anti-CD4 monoclonal antibodies (mAbs) suitable for specific immunoscintigraphy of human/ experimental arthritis. Following intravenous injection, however, mAbs are present both in the free form and bound to CD4-positive, circulating monocytes and T-cells. Thus, the present study aimed at analyzing the relative contribution of the free and the cell-bound component to the imaging of inflamed joints in experimental adjuvant arthritis (AA). Methods: AA rat peritoneal macrophages or lymph node T-cells were incubated in vitro with saturating amounts of 99mTc-anti-CD4 mAb (W3/25) and injected i.v. into rats with AA. Results: In vitro release of 99mTc-anti-CD4 mAb from the cells was limited (on average 1.57%/h for macrophages and 0.84%/h for T-cells). Following i.v. injection, whole body/joint scans and tissue measurements showed only negligible accumulation of radioactivity in inflamed ankle joints (tissue: 0.22 and 0.34% of the injected activity, respectively), whereas the radioactivity was concentrated in liver (tissue: 79% and 71%, respectively), kidney, and urinary bladder. Unlike macrophages, however, anti-CD4 mAb-coated T-cells significantly accumulated in lymphoid organs, the inflamed synovial membrane of the ankle joints, as well as in elbow and knee joints. Conclusion: While the overall contribution of cell-bound mAbs to the imaging of arthritic joints with anti-CD4 mAbs is minimal, differential accumulation of macrophages and T-cells in lymphoid organs and the inflamed synovial membrane indicates preferential migration patterns of these 2 cell populations in arthritic rats. Although only validated for 99mTc-anti-CD4 mAbs, extrapolation of the results to other anticellular mAbs with similar affinity for their antigen may be possible.


1989 ◽  
Vol 61 (03) ◽  
pp. 409-414 ◽  
Author(s):  
M Rånby ◽  
G Nguyen ◽  
P Y Scarabin ◽  
M Samama

SummaryAn enzyme linked immunosorbent assay (ELISA) based on goat polyclonal antibodies against human tissue plasminogen activator (tPA) was evaluated. The relative immunoreactivity of tPA in free form and tPA in complex with inhibitors was estimated by ELISA and found to be 100, 74, 94, 92 and 8l% for free tPA and tPA in complex with PAI-1, PAI-2, α2-antiplasmin and C1-inhibitor, respectively. Addition of tPA to PAI-1 rich plasma resulted in rapid and total loss of tPA activity without detectable loss of ELISA response, indicating an immunoreactivity of tPA in tPA/PAI-1 complex of about l00%. Three different treatments of citrated plasma samples (acidification/reneutralization, addition of 5 mM EDTA or of 0.5 M lysine) prior to determination by ELISA all resulted in increased tPA levels. The fact that the increase was equally large in all three cases along with good analytical recovery of tPA added to plasffi, supported the notion that all tPA antigen present in plasma samples is measured by the ELISA. Analysis by ELISA of fractions obtained by gel filtration of plasma from a patient undergoing tPA treatment identified tPA/inhibitor complexes and free tPA but no low molecular weight degradation products of tPA. Determinations of tPA antigen were made at seven French clinical laboratories on coded and randomized plasma samples with known tPA antigen content. For undiluted samples there was no significant difference between the tPA levels found and those known to be present. The between-assay coefficient of variation was 7 to 10%. In conclusion, the ELISA appeared suited for determination of total tPA antigen in human plasma samples.


1977 ◽  
Vol 38 (02) ◽  
pp. 0494-0503 ◽  
Author(s):  
D. S Pepper ◽  
D Banhegyi ◽  
J. D Cash

SummaryAntithrombin III (AT III) complexes were isolated from human serum by affinity chromatography and gel filtration. In the first step of the preparation, using heparin-agarose chromatography, we observed that the complexed form of AT III bound less strongly to the gel than the free form and that about half of the AT III was free. With further purification a 2.5 × 105 molecular weight complex was isolated. Using 125I labelled human thrombin, this complex was radioactive indicating the presence of thrombin. Only in a synthetic thrombin-AT III system was a 9 × 104 molecular weight complex detected, but not in serum. These facts suggest that in serum AT III complexes may exist in a polymeric form. Also, an AT III antigen derived from the original AT III molecule, but not complexed, was isolated which may be a degradation product.Abbreviations used: AT-III, antithrombin III. Hepes, N-2-Hydroxyethylpiperazine-N-2-Ethanesulphonic acid.


1997 ◽  
Vol 78 (02) ◽  
pp. 864-870 ◽  
Author(s):  
Hideki Nagase ◽  
Kei-ichi Enjyoji ◽  
Yu-ichi Kamikubo ◽  
Keiko T Kitazato ◽  
Kenji Kitazato ◽  
...  

SummaryDepolymerized holothurian glycosaminoglycan (DHG) is a glycosaminoglycan extracted from the sea cucumber Stichopus japonicusSelenka. In previous studies, we demonstrated that DHG has antithrombotic and anticoagulant activities that are distinguishable from those of heparin and dermatan sulfate. In the present study, we examined the effect of DHG on the tissue factor pathway inhibitor (TFPI), which inhibits the initial reaction of the tissue factor (TF)-mediated coagulation pathway. We first examined the effect of DHG on factor Xa inhibition by TFPI and the inhibition of TF-factor Vila by TFPI-factor Xa in in vitro experiments using human purified proteins. DHG increased the rate of factor Xa inhibition by TFPI, which was abolished either with a synthetic C-terminal peptide or with a synthetic K3 domain peptide of TFPI. In contrast, DHG reduced the rate of TF-factor Vila inhibition by TFPI-factor Xa. Therefore, the effect of DHG on in vitroactivity of TFPI appears to be contradictory. We then examined the effect of DHG on TFPI in cynomolgus monkeys and compared it with that of unfractionated heparin. DHG induced an increase in the circulating level of free-form TFPI in plasma about 20-fold when administered i.v. at 1 mg/kg. The prothrombin time (PT) in monkey plasma after DHG administration was longer than that estimated from the plasma concentrations of DHG. Therefore, free-form TFPI released by DHG seems to play an additive role in the anticoagulant mechanisms of DHG through the extrinsic pathway in vivo. From the results shown in the present work and in previous studies, we conclude that DHG shows anticoagulant activity at various stages of coagulation reactions, i.e., by inhibiting the initial reaction of the extrinsic pathway, by inhibiting the intrinsic Xase, and by inhibiting thrombin.


2011 ◽  
Vol 29 (supplement) ◽  
pp. 283-304 ◽  
Author(s):  
Timothy R. Brick ◽  
Steven M. Boker

Among the qualities that distinguish dance from other types of human behavior and interaction are the creation and breaking of synchrony and symmetry. The combination of symmetry and synchrony can provide complex interactions. For example, two dancers might make very different movements, slowing each time the other sped up: a mirror symmetry of velocity. Examining patterns of synchrony and symmetry can provide insight into both the artistic nature of the dance, and the nature of the perceptions and responses of the dancers. However, such complex symmetries are often difficult to quantify. This paper presents three methods – Generalized Local Linear Approximation, Time-lagged Autocorrelation, and Windowed Cross-correlation – for the exploration of symmetry and synchrony in motion-capture data as is it applied to dance and illustrate these with examples from a study of free-form dance. Combined, these techniques provide powerful tools for the examination of the structure of symmetry and synchrony in dance.


1959 ◽  
Vol XXXII (II) ◽  
pp. 195-208 ◽  
Author(s):  
E. Diczfalusy ◽  
Anne-Marie v. Münstermann

ABSTRACT From the ethanol extract of 100 full term placentae approximately 200 μg of an α-ketolic Kober chromogen have been isolated in a »free« form. The evidence obtained indicates that this α-ketolic Kober chromogen is identical with 16-oxooestradiol-17β.


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